Coupling means for radio shielded ignition harness



June 11, 1946. I D, INGALLS 2,402,050

COUPLING MEANS-FOR RADIO SHIELDED IGNITION HARNESS Filed Feb. 25, 1944INVENTOR Patented June 11, 1946 UNITED STATES PATENT OFFICE COUPLINGMEANS FOR RADIO SHIELDED IGNITION HARNESS David Ingalls, Westfleld, N.J. Application February 25,1944. Serial No. 523,836

6 Claim.

, tus is usually enclosed in-a radio shield which prevents the emanationof such waves. To provide such shield the spark plugs are each enclosedin a metal casing and the magneto, distributor, etc. are enclosed in ametal radio shielding casing. The conductors from the magneto anddistributor are led through a metal radioshielding conduit to themanifold. The manifold is a metal radio-shielding conduit which may beof any desired shape to accord with the engine to which it is afllxed,being usually straight where the engine cylinders are arranged instraight lines and curved or arc-shaped so as to embrace the engineshaft when the engine is of the radial type as is usually employed inaeroplanes. From the manifold individual metal radio-shielding conduitsfor the ignition wires lead to the radioshielding casings of the sparkplugs respectively. This construction is well known and theradioshielding conduits between the distributor and the spark plugs,including the manifold, with the ignition conductors within, arecommonly referred to as a radio-shielding harness.

The ignition conductors passing from the magneto through the manifoldand spark plug leadsto the spark plugs, are the usual insulatedconducting cables, that is conductors with insulation molded thereon, asproduced by the cable manufacturers.

It has been found in practice that deleterious moisture, condensate,etc. is liable to be formed especially in the spark plug lead conduitsand in order to prevent such deleterious matters from entering themanifold it has been found desirable, if not essential, that the sparkplug lead conduits should be sealed from the manifold. It is animportant object of the invention to provide an improved means foreffectin such sealing.

It is further desirable, if not essential, in order that the harness mayfunction most efficiently as a radio-shield, that each spark plug leadradioshielding conduit and the manifold be electrically connected, andit is desirable that this connection should be of as low resistance aspossible.

It is therefore, a'further object of the invention to provide improvedmeans whereby good electrical connection of the character as specifiedshall be secured.

The conduit of a spark plug lead is usually secured to the outlet Of themanifold by a nut. If such nut, under the vibration incident to its useon the engine, or for any other reason, should become loose, the resultmight be detachment and dislocation of the conduit from "the manifoldwith obvious disastrous results, and even the mere loosening of theparts, would detract from the efficiency of the shielding and afford anop portunity for deleterious moisture to enter the harness.

A further object of the invention is to provide improved means forlocking the parts against looseningas referred to. I

A further object of the invention is to provide a unitary structurewhereby the sealing; locking I and electrical connecting as referred tomay be eiilciently and simply accomplished.

Other and ancillary objects of the invention will appear hereinafter.

In the accompanying drawing which illustrates the invention- Figure 1 isa side elevation of sufficient of a manifold and a spark plug lead of aradio-shielding ignition harness to show the application of theinvention thereto, certain parts being omitted and certain parts brokenaway, the manifold outlet and the adjacent endof the spark plug leadtogether with the connecting and sealing means therefor being shown inaxial section;

Figure 2 is a section on the line 2-2 of Figure 1;

Figure 3 is a side elevation, partly in section, of a gasket employed inthe assembly of Figure 1;

Figure 4 is an end elevation of the gasket of Figure 3 viewed from theleft of the latter figure;

Figure 5 is a view similar to Figure 3 showing modified type ofconstruction; I

Figure 6 is an end elevation of the gasket in Figure 5 viewed from theleft side;

Figure 7 is a partial side elevation with some portions in sectionshowing a modified applicathe outlet 2 which may be a separate structuresecured to the manifold or may be an integral part of the manifold. Atits outer end the outlet 2 has the screw-threads 3. These parts are ofmetal so as to form a radio-shield. The spark 3 plug lead is flexible,comprising the flexible, radio-shielding conduit including the flexibletube 4 which may be a strip-formed corrugated tube as shown in thepatent to Louis H. Brinkman No. 1,198,392 upon which is the covering 5of braided, flat, metal strips. Within the conduit is the ignition cablecomprising the stranded flexible conductor 6 covered with insulation 1.This conductor extends outwardly to the vicinity of the spark plug andis connected therewith, while the metal conduit comprising the tube 4and braided on covering 5 is connected at its outer end to a spark plugelbow or a spark plug shield in a well known manner.

The conductor cable extends inwardly through the outlet 2 and themanifold l and from the manifold I through a radio shielding conduit(not shown) to the distributor (not shown) in a well known manner.Soldered to the tube 4 and its braided covering 5 is a ferrule 8 havinga radial flange 9. One portion of the flange 9 extends inwardly so as tosubstantially cover the end of the tube 4 and braided covering 5.Another portion of the flange extends outwardly and is engaged by aflange ill on a nut I l swiveling on the ferrule 8 and havingscrew-threads cooperating with the screw-threads 3 upon the manifoldoutlet.

Referring now'to Figures 3' and 4, the gasket therein shown comprisesthe circular resilient insulating body I! which may be of rubber,compounds thereof or synthetic imitations thereof, v

such as Neoprene. This body has a small taper or draw, growing smallerproceeding toward the right of Figure 3 whereby the body may be wedgedinto a circular member in a manner similar to inserting a cork in theneck of a bottle.

This body has a central hole l3 through which the ignition cable in theassembled structure may pass. Surrounding the body I2 is a metal band i4having the outwardly extending flange l5, and the inwardly extendingflange Hi. In the body i2 is a circumferential groove Il within whichthe flange i6 enters. It will be seen that the resilient, insulatingmaterial of the body l2 projects at l8 upon one side of the band andthat such body also projects beyond the other edge of the band M. Itwill be seen that the flange i5 is slitted inwardly from its edge andthe tongues thus formed are twisted so that their edges form teeth uponboth sides of the flange. The teeth at the flange sides may be formed inany other suitable manner.

In assembling the gasket of Figures 3 and 4 into the apparatus as shownin Figure 1, the ignition cable is drawn through the central hole 13,

the hole being of such diameter with relation to the cable that theresilient body will press tightly against the cable.

The gasket is then inserted into the manifold outlet 2 in which ittightly fits after the manner of a cork in the neck of a bottle.

The toothed flange I! will enter between the ferrule flange 9constituting the end of the spark plug lead conduit and the end of theoutlet 2. On drawing the conduit and manifold outlet together byscrewing up the nut ii, the flange I! will be gripped between theferrule flange 9 and the end of the outlet. With the parts thusassembled, the manifold will be sealed from the spark plug lead conduitby the resilient body and such body will be held in position by theflange l5 gripped between the ferrule 9 and the end of the manifoldoutlet, the body being securely held against longitudinal movement withrelation to the band II and flange ill by the flange I. Also the teethof the flange l5 will abrade and bite into the end of the outlet and itsopposing ferrule thereby forming a good electrical connection betweenthe manifold and the spark plug lead conduit. Also the biting of theteeth into the outlet end and ferrule will lock them against relativerotative movement and thereby prevent unscrewing and loosening of thenut which otherwise might be caused by such movement.

It will be observed that the end of the body I! bears against theferrule flange 8 whereby there is a seal against seepage from theatmosphere through the nut threads into the spark plug lead conduit. Thetaper IS in the body at the end where it bears against the ferrulerenders the end of the body bearing against the ferrule more flexiblewhereby it can spread out and be more thoroughly sealed against theferrule; also such taper provides for greater radii of curvature of thecable as the spark plug lead flexes, and avoids sharp bends of the cableas might occur if the cable abruptly left the body as would be the caseif the cable were tightly gripped by the body to the end of the latter.

As an alternative to the gasket shown in Figure 3 an assembly isillustrated in Figures 5 and 6 wherein the metal band 14' has a rubberor similar substitute moulded to form a continuous outturned flange withthe projections IE. it will be noted that projections iii are imbeddedin themoulded plastic so that they form a continuous planar surface onboth sides of the flange.

Utilizing this type of construction in an assembly such as is shown inFigure 1, a moisture-proof seal is effected between the ferrule 9fastened to the flexible conduit and to outlet 2 attached to the radioshielding manifold in addition to performing the function of a lockingdevice between the mating parts and providing good low resistanceelectrical contact between the joining parts.

Figure '7 illustrates a modifled type of gasket adaptable to fittingutilizing tapered conical seat rather than a barrel type of fitting asshown in Figure 1. The gasket shown in the assembly Figure '7 has atapered insulated flexible body I! to which is assembled the metal disk14 in a moulded angular circumferential groove H. The disk I! may alsohave a continuous outturned flange serving identical functions as thatoutturned flange previously described and including web portions ofmoulded rubber or similar material between the metal projections l5"integral with the disk H.

Because of the resiliency of the web between the projections I5, Figure6, and I5", Figure 8, it will be noted that it is possible for theprojections to twist slightly to effect a locking condition; whereuponthe resilient material from the web is displaced to clearances providedoutside of the web. In any case, this twisting action does not affectthe moisture seal of the web, nor does it affect the electrical contactbetween mating parts of the assembly.

While the invention has been illustrated in what is considered its bestapplication, it may have other embodiments without departing from itsspirit and is not therefor limited to the structure shown in thedrawing.

What I claim is:

1. In a, radio shielded ignition harness for an internal combustionengine, the combination with a manifold having an outlet, of a radioshielding conduit of a spark plug lead, a cable extending from saidmanifold through said outlet and into said conduit, a. resilientinsulating body through which said cable passes, said body having anopening for the passage said cable and tightly fitting thereagainst andalso tightly fitting within said outlet, 3. metal band surrounding saidbody and having a flange extending outwardly, means for drawing saidoutlet and conduit together, said flange extending between and grippedby said conduit and outlet when drawn together, said body being pressedagainst said conduit and said outlet, said flange having teeth at itssides engaging with said conduit and said outlet and a web of resilientinsulating material between the teeth and integral with the resilientinsulating body.

2. In a radio shielded ignition harness for an internal combustionengine, the combination with a manifold having an outlet, of a radioshielding conduit of a spark plug lead, a cable extending from saidmanifold through said outlet and into said conduit, a resilientinsulating body having conduit and said outlet, and said body having acircumferential groove into which said inwardly extending flange enters.

3. A gasket comprising in combination a resilient insulating body havinga central hole, a metal band surrounding said body and having a flangeextending outwardly, said body extending upon both sides of said band,said flange being toothed and including a web of resilient insulatingmaterial between the teeth which is integral with the resilientinsulating body.

4. A gasket comprising in combination a resilient insulating body'having a metal band surrounding said body and having two flanges oneextendingoutwardly and the other extending inwardly, said outwardlyextending flange being toothed and having a web of resilient insulatingmaterial extending between the teeth which is integral with theinsulating material of said body and said body having a circumferentialgroove into which said inwardly extending flange enters,

said body extending upon both sides of said band.

5. In a radio shielded ignition harness for an internal combustionengine, the combination with a manifold having an outlet, of a radioshielding conduit of a spark plug lead, a cable extending from saidmanifold through said outlet and intosaid conduit, a resilientinsulating body through which said cable passes, said body having anopening for the passage of said cable and tightly fitting thereagainstand also tightly fitting within said outlet, a metal band surroundingsaid body and having a, flange extending outwardly, means for drawingsaid outlet and conduit together, said flange extending between andgripped by said conduit and outlet when drawn together, said flangehaving teeth at its sides engaging with said conduit and said outlet anda web of resilient insulating material-between the teeth and integralwith the resilient insulating body.

6. A gasket comprising in combination a resilient insulating body havinga centralhole, a metal band surrounding said body and having a flangeextending outwardly, said flange being toothed and having a web ofresilient insulating material between the teeth which is integral withthe resilient insulating body.

- DAVID INGAILS.

